The main function of the skin is to protect the underlying tissue from the external environment. It thus prevents among other things the penetration of pathogenic microorganisms into the body. The skin and mucous membranes are of course populated by a wide variety of microorganisms which often live as commensals in a relatively stable composition on the surface and support the protective function of the skin. In the ideal case bacteria having a positive health effect will be dominant over harmful microorganisms occurring at the same time. If this system gets out of balance, negative effects on the person's health and well-being are virtually predestined.
Pathogenic microorganisms have the ability to adhere specifically to the structures of the epidermis through binding proteins. For example, the presence of adhesins with which the microorganism can adhere to fibronectin structures is known to occur with the pathogenic strain Staphylococcus aureus (Bingham, R. J. et al. 2008, O'Neill, E. et al., 2008).
Pathogenic microorganisms usually have a higher potential for adhering to the host, which thus explains the increased virulence. The presence of extremely small lesions or other injuries in the top layers of skin increases the risk of invasion of pathogenic microorganisms.
Furthermore, bacterial infections of the wound surfaces especially in healing of wounds may lead to complications. There is the risk first that acute wound will not heal and will lead to chronic wounds. The microflora of these chronic wounds is highly complex and it is known that a variety of microorganisms can have a deleterious effect on the wound healing process (Davies et al. 2004, Kirketerp-Moller et al. 2008).
Aerobic bacteria, e.g., Pseudomonas aeruginosa and Staphylococcus aureus have be identified as the main pathogens in wounds. The inflammatory phase of wound healing normally serves to combat potentially pathogenic microorganisms and for cell regeneration. However, poorly healing or refractory wounds often occur in patients who are already immunosuppressed and have a reduced inflammatory response. This weakened immune response can no longer provide effective defense against primary wound bacteria, so the bacteria penetrate into the wound and form colonies, which are organized as biofilms (James et al. 2008).
The biofilms are not only resistance to the defense system of the host but also planktonic cells or microcolonies (Fux et al. 2005, Sheldon 2005). Due to the impaired immune system, the biofilm keeps the wound healing process in the inflammation phase with the result that there are elevated concentration of matrix metalloproteins such as elastase, plasmin and thrombin, for example, which in turn degrade the growth factors and their receptors that are essential for healing (Mast and Schultz 1996).
Furthermore, the elevated concentrations of free oxygen radicals and inflammatory cytokines led to severe damage to the host cells (James et al. 2003, Moseley et al. 2004).
Therapeutic agents capable of eliminating the biofilm and thus combatting the causes of chronic and refractory wounds have been described in the prior art.